Manufacturers of light emitting diodes must perform visual inspections for the control and quality assurance of internal wiring connections in the diode capsules. In order to carry out the inspection, the manufacturers immerse the diodes in isopropyl alcohol, and with the help of microscopes, they observe through the transparent dome of the diodes wafers and their connections that are located at the bottom of the diodes capsules.
In view of the need to reduce production costs and eliminate the use of alcohol and hazardous substances, the device described below of the present invention was developed and can be used as a tool in the quality assurance and control of the production of light emitting diodes, avoiding the handling of flammable materials.
When the diodes are observed in dry format, the transparent dome of the diode capsule disperses the light and it is not possible to observe the wafer and its connections inside the diode. Submerging the diodes in alcohol, allows the observation, but involves an increase in costs, increase in production times, and the need to adapt the spaces in the production lines for the extraction of vapors, and handling of flammable or hazardous materials.
There are records in patent documents on this subject, such as U.S. Pat. No. 8,885,040, which has an observation device totally different from the device of the present invention; U.S. Patent Application 2009/0136120A1, which discloses an LED inspection device utilizing ultraviolet light; U.S. Patent Application 2012/0249779A1, which discloses a device utilizing both visible and ultraviolet light; as well as the patent application PCT WO2007140984A1, which shows an arrangement of lenses for illumination and observation of the objects. All these documents are totally different from what is proposed by the present invention. The parts and detailed characteristics of this device are clearly shown in the following description and in the accompanying drawings.